Brush drilling machine



. J1me 1936- 1.. s. TERH UNE I BRUSH DRILLING MACHINE Original Filed May 25, 1929 8 Sheets-Sheet l INVENT ATTORNEY June 16, 1936. 1., B. TERHUN'E BRUSH DRILLING MACHINE 8 Sheets-Sheet 2 Original Filed May 23, 1929 INVENTOR XMA- ATTORN June 16, 1936. L. B. TERHUNE BRUSH DRILLTNG MACHINE Original Filed May 23,

1923 8 Sheets-Sheet 3 I II I I W W I I W N :1. eiwww lf m mm QM I mm I m $6 NM June 1936- 1.. B. TERHUNE BRUSH DRILLING MACHINE Original Filed May 25, 1929 8 Sheets-Sheet 4 June 16, 1936.

L. B. TERHUNE BRUSH DRILLING MACHINE Original Filed May 23, 1923 8 Sheets-Sheet 5 kg QR INVENTOR irkg d 1% ATTORN EY June 16, 1936. B. TERHUNE BRUSH DRILLTNG MACHINE 1929 8 Sheets-Sheet 6 Original Filed May 25,

INVENTOR ATTOR EY 8 Sh'eets-Shegt '7 June 16, 1936. TERHUNE BRUSH DRILLING MACHINE Original Filed May 25, 1929 INVENTOR ATTORNEY June 1936. B. TERHUNE BRUSH DRILLING MACHINE 8 Sheets-Sheet 8 Original Filed May 23, 1923 3 fl 6 a w 6 W 8 7 6 40 1 m M H H H! w 1 Jfl g 5 a 0 1 W Z x m n 1 u m H" w 1 H m v d z 2 m 1 h v 5 M r i 2 ,M w H I 3 I B w 6 m 5 J LH o w 4 E lm 1 1 1 1 w e a 1 a 1 I O 3 HWI H I H VUJIII:\I\..I 6 B Z M INVENTOR a TM BY ATTQRNEY Patented June 16, 1936 UNITED STATES BRUSH DRILLING MACHINE Leonard B. Terhune,

Newark, N. J., assignor to Dupont Viscoloid Company,

Wilmington, Del.,

a corporation of Delaware Original application May 23 1929, Serial No.

365,495, now vember 28 1933.

Patent No. 1,937,101, dated No- Divided and this application October 25, 1933, Serial No. 695,130

12 Claims.

My invention relates particularly to a mechanism for drilling holes in brush blanks, in the manufacture of brushes generally, and which has application to the manufacture of brushes of any desired type.

This application is a division of my application upon Drilling and inserting mechanism for brush machines, Serial No. 365,495, filed May 23, 1929.

The object of my invention is to provide a mechanism for drilling holes in brush blanks in all types of brushes, for example, toothbrushes, hand-scrub brushes, etc. The object of my invention is particularly to provide a drilling machine which is applicable to machines in which the brush blanks are designed to be held or moved in any manner, although the machine made in accordance with my invention is especially applicable for use in connection with the machine disclosed in my application entitled Brush holders for brush making machines, Serial No. 338,978, filed February 11, 1929, Patent No. 1,913,863, granted June 13, 1933, and my application Serial No. 365,495, Patent No. 1,937,101, granted November 28, 1933, above referred to. The object of my invention is to provide, also, a mechanism comprising operating parts which include multiple drilling devices for use, if desired, in connection with a single brush holder mechanism, such as that shown in my applications above referred to, and which, nevertheless, is embodied in a unitary mechanism. Again, the object of my invention is especially to provide a mechanism for operating the drilling devices which is not only applicable to many different methods of holding and moving the brush blanks, but which is compact and which, therefore, may be constructed and maintained at a minimum of expense and with a minimum amount of labor. I have accomplished this end particularly by reason of the fact that the drilling mechanism is operated from a cam shaft which is located substantially centrally in the machine. This is of particular importance, also, by reason of the fact that this cam shaft may also be the main shaft operating the brush holder holding the blanks for cooperation with the drilling mechanism. Also, the object of my invention is to provide an interchangeable drill holding unit so that the same may be replaced by other similar units when repairs are needed, or when brushes of different types are desired to be manufactured, in which the placing of the holes in the brush blanks is sufliciently different to require a different location for the multiple drills used in the machine. This arrangement of the parts also permits, as will be readily understood, the different parts of the mechanism to be removed without interfering with the operation of the remaining units which are contained in the machine while the others are being repaired, replaced, etc. Further objects of my invention will appear from the detailed description of the same hereinafter.

While my invention is capable of embodiment in many different forms, for the purpose of illustration I have shown only one embodiment of my invention in the accompanying drawings, in which- Fig. 1 is a plan view of a drilling machine made in accordance with my invention;

Fig. 2 is a side elevation of the same;

Fig. 3 is a front view of the same;

Fig. 4 is a horizontal section of the same;

Fig. 5 is a rear elevation partly in section; 1

Fig. 6 is a transverse vertical section showing the nozzle unit; 1

Fig. '7 is a vertical section of the same taken at right angles to the section shown in Fig. 6;

Fig. 8 is a detail perspective view of the needle bar and needle;

Fig. 9 is a fragmentary perspective view enlarged, showing the picker and picker knife operating bars;

Fig. 10 is an enlarged detail in section showing the arrangement of the picker and picker knife in the removable unit containing the same;

Fig. 11 is an enlarged horizontal section-showing the picker and picker knife;

Fig. 12 is an enlarged fragmentary perspective view showing the wire from which the anchors are made and the rolls for feeding same;

Fig. 13 is a fragmental detail section of a brush blank showing the bristles as carried in one of the holes and held therein by the anchor made from the wire referred to;

Fig. 14 is a vertical section through the brush holder mechanism; and

Fig. 15 is an elevation of a spring plunger used as a pawl in connection therewith.

In the machine which I have used, by way of illustration of my invention, the arrangement is applicable for use in the manufacture of brushes of any desired type, or kind, but is especially applicable to the manufacture of toothbrushes, by way of example. In this machine I have shown a main operating shaft I carried in any suitable bearings 2 supported on a main frame 3, and secured thereto by bolts 3a, carried on a base 4, which is shown in Fig. 2 with a broken line at the part thereof which may be in the inoperative position for sired journal bearings for this end of Ithesaid shaft. This main shaft I may be driven from any suitable source of power, ,as, for example, "by means of a pulley 5 tightly mounted on the shaft I, carrying a band 6 on its periphery designed to be driven from any suitable source of powergas, for example, an electric motor, etc. Mounted on said pulley 5 there is a ring gear 1 which drives a series of six intermediate gears'8,"9,' [0,1 I,

l2, and I3, which are mounted on stud shafts I24 carried in a removable spider l5 adapted to be secured to the journal bearing '2 by means of screws'l6. Thesegears 8, 9,=I*6, l I, I2, and I3 are "provided for-the operation of six drills H, I8, l9,

20,-2! and 22, all of which are driven'by a-suitable train of gearing in each instance-the gearing for these six drills being exactly the-same for driving each-particular drill. Accordingly, only :one of thesetrains of gearing will be. described indetail. The intermediate gear 8 has securedthereto a larger gear'23 which in turn'meshes' with agear '24'attached toa drill spindle 24a carrying the drill l 1 rotating in a bushing 25 inthe said spider l5, andprovided with a drill chuck 25 of any desiredtype' on the spindle 24a. The-drill'spindle 24a with the attached gear 24 is, arranged to, be longitudinally slidable manually out of engagement with thebrush blank'bymeans of a slide 26a having a thumb piece 26b for the movement of thesame, and a slot26c for receivinga screw 26d which is tightened in place-during the time when the drill I1 is to be operated but-which willbe loosened when ittis desired tothrowthe particular drill out'of operation. A recess'26e in the slide 26a cooperates with-a spring-pressed ball 26] in the retracted position to'holdthedrill repairs, replacements, etc. The slide 26a is connected to'the spindle 24a by means of a yoke 26g located injan annular recess 26h on theface of the gear 24.

'It will be understood that the -machine is equipped, not only with multiple drills'as above described, but also with duplicate inserting mechanisms for inserting the bristles into the "brush blanks, although only "one of such.inserting mechanismwill ;be describedin detail as both of them are constructed and operated in exactly the same mannenexcept that these two inserting mechanisms are constructed as rightand, lefthand'devices', respectively, asthey are'located on opposite sides of the machine.

'I'heshaft 'l on the other side vof the spider [.5 from the gearing just described, carries acam wheel2'! having -a cam groove 28 in its face in which there is'designed to be-moved a roller 29 for operating the picker. This'roller- 29is carried on a studshaft 30 passing intoa picker bar 3| which is guided for transverse movement within a U-shaped picker knife bar 32. Both the picker bar 3| and the picker knifebar 32 are arranged to reciprocate in a groove 33 in the main frame'3. At its end the picker bar 3| has a right angle extension 34 which rests withina recess 35 in the picker 36, which reciprocates transversely of the machine in a groove 31 located in a-removable bar 38 adapted to-be secured-to extending from the arm 65 10, secured in a'groove 1|, carried in a vertically reciprocating bar l2 which is arranged to'reciprocate in the main the main frame by means of screws 39. A cover plate 40 fits over the top and side of said picker 36 and is secured to said bar by means of screws 4|. It will be noted that the picker 36 hasavertical recess 42 to enable it to pick a 5 charge of bristles from azbristle feeding passageway 43 provided with a continuously fed supply of bristles 44 supplied thereto from any suitable "bristle feeding mechanism, as, for example, the mechanismzas disclosed in my application upon Bristle magazines for brush making machines,

SerialNo. .338,979,'filed February 11, 1929, it being understoodthat on the opposite side of the machine there is a duplicate of this bristle feeding .zmechanism, except that the two feeding mechanisms-are arranged in the right and left hand po- =sitions, :respectively. Also, within the picker 36 there is provided a, picker knife or a separator bar-45 having a pointed edge 46 at its extreme end to separate the charge of bristles in the recess 4-2 from the bristles carried in the passageway "43 and=holdtherri therein until they are carried by the'simultaneous movement'of the picker 36 andthe picker knife 45 to a bristle inserting nozzle 41, it being understood that another such nozzlefla; with cooperating parts, is located on the opposite side of the machine. This picker knife '45 is movedbymeans of aright angle extension 48 resting within a recess 49 in the side of the picker'knife 45, which right angle extension is carriedupon the picker knife bar 32. This 'pickerknife'bar 32*is movedby means of a cam roller 5n-whichoperates within a cam groove 5| the-face'of a cam wheel 53 carried on the shaft l'adjacent to'the cam wheel 21.

In order-to feed to the mechanism a wire 54 'from which there is to be cut fiat anchors 55, this wire 54 is supplied to the machine by means of two feed rollers '56 and5'l, the "former being carried in'bearings 58 secured to the main frame =andthe latter-in asliding carriage 59 pressed =downwardly bysprings-GO on rods 6| having nuts 62 "thereon for the adjustment of compression of said springs, which rods project upwardly from the-mainframe. The feed roller 56 is operated-by means ofaratchet wheel 63 secured thereto, and which is driven by means of a "spring 'pressed pawl 64 carried in an arm 65 pivoted onthe shaft carrying the feed roller 56. "This'arm 65 has'on its outer end a roller 6650 which is 'held against an outer cam periphery 2! by-means of a spring 68 to the spider I5. In this "way thewire 54 is fed across a recess 69 in whichthereis arranged'to reciprocate a punch in the face of a block 61 of the cam wheel frame, a tapered pin 13 being provided for tightly'securing said block H within the bar 72.

This-bar 12 is'reciprocated by means ofga pin F4 "extending laterally therefrom and thence into 'a'slot 15 in alever 16 carried on a fixed pivot T! by the main frame, which lever 16 has a roller"18 adapted to be moved by a cam groove'65 "79 in the front face of the cam wheel 53. Like mechanism is provided on the other side of the ,"machine for operating the punch on that side ;of the same, the same roller 18 being provided for this purpose and having a pin extension 18a,

on which said roller is pivoted for cooperating with a slot 181) in thesaid lever onthe other side of the machine.

In order to complete the insertion of the bristles withthe anchor'into a brush blank 8037-5 which is supported on any suitable brush blank holder 81, such, for example, as that shown in my application Serial No. 338,978 above referred to, I have provided a needle operating mechanism. This is comprised of a cam wheel 82 which is also mounted tight on the shaft 1, and which has a cam groove 83 on its periphery for the operation of a roller 84 on a needle bar 85. This needle bar 85 operates in a movable channel-shaped box 86 which is secured to the main frame 3 by means of screws 81 and 88 which pass through ears extending from the said channel-shaped box 88. This channel-shaped box 86 is, furthermore, arranged to support in place the nozzles 41 and 41a. to which the latter is secured by screws 86a. A cover plate 86b is also provided over the rear end of the channel-shaped box 86 to which it is attached by screws 860. A needle 89 is secured in the top of a projection 98 on the bar 85 by means of a clamping plate 9| having screws 92 to hold the same in place thereon, a thumb recess 93 being provided at one side thereof to permit the needle 89 to be grasped for the adjustment of the same longitudinally of the bar 85. This bar 85 is so located with regard to the nozzle 41 as to adequately support the needle 89 without danger of bending or breaking the same and without requiring the soldering thereto of any bracing or holding memher at the rear of the same. This is accomplished in the following manner: The nozzle 41 is divided into a lower grooved portion 94 having a groove 95 therein for carrying the said needle, and an upper portion 98 for covering the same, both portions being cut out to provide an opening 91 extending entirely through the nozzle vertically and in such a position as to support one half of the width of the needle, as shown in Fig. 4, when the needle is in retracted position. This provides an adequate support for the needle, by supporting one half of the width of the same during the initial travel of the needle when no great strength is required therein, and when the load is taken up by the needle the recess 91 is almost entirely closed by the bar 85 and thereby leaves only a negligible portion of the needle unsupported at this period of the operation. The movement of the needle 89 is thus coordinated with the movements of the picker mechanism, and the anchor punch mechanism so that the said needle, when it reaches the aperture 69, will pick up the anchor and the tuft of bristles in advance of the same, thus folding the bristles and forcing the tuft of bristles with the anchor between the fold out through the end of the nozzle 41 into the brush blank 88 by causing the anchor 55 to cut slightly into the sides of the drilled hole of the brush blank until the tuft of bristles is thus securely anchored at the bottom of the drilled hole. It will be understood that when the tuft of bristles with the anchor 55 carried in the rear thereof, reaches the position where it is about to enter the brush blank, the brush blank 80 will already have been moved up to this point by any suitable means or mechanism, such, for example, as that shown in my application Serial No. 338,978, and that after the insertion of the tuft has been completed in this manner the brush blank will again be moved to withdraw the bristles from the nozzle 41 and to the next proper position for the insertion of the next tuft therein by said mechanism.

It will be understood that the two inserting nozzles 41 and 41a may be operated simultaneously for the insertion of bristles in the respective brush blanks located opposite thereto, or, if desired, one of them may be removed at any time without interrupting the operation of the other, thereby continuing the operation of the brush blank holder, notwithstanding the removal of one set of mechanisms. When it is desired to remove the inserting mechanism this is readily accomplished merely by removing the screws 81 and 88 and then pivoting the unit upwardly on the roller 84 until the adjacent parts are cleared.

Likewise, it will be understood that the picker unit may be readily removed by removing the screws 39 and lifting the same away from the right angle extensions 34 and 48 so that a new picker mechanism may be inserted, and so that, if desired, the operation of the machine may be continued without interruption as to the remaining picker mechanism in the apparatus. As above noted, there are provided in the machine two sets of drills l1, l8 and I9 and 20, 2|, and 22, which are provided for preparing the holes in the brush blanks for the nozzles 41a and 41 respectively. The last drill of the particular set, just before its particular nozzle, may, if desired, be provided with a reamer. However, the main purpose of providing the plurality of drills, all of which are designed to drill the same holes three times in succession for the particular nozzle, is to prevent stoppage and interruptions in the operation of the machine, owing to the fact that one of the greatest causes in the ineffective operation of brush making machines is the inaccurate and ineffective preparation of the holes so as to make them of exactly the same size and shape for the receipt of the tufts of bristles to be inserted therein. It will be readily understood that where each of the holes is thus drilled three times, or drilled twice and reamed once the holes will acquire a uniform size and shape and thus greatly conduce to the effective and uninterrupted operation of the machine. Furthermore, it will be realized, nevertheless, that, if desired, one or two of the group of three drilling operations may be dispensed with, either voluntarily or due to breakages therein, without necessarily preventing for the time being the continued operation of the machine as a whole. Besides, 'if more than two of the drills of a set are thrown out of action, accidentally or otherwise, the inserting mechanism which is used to cooperate therewith may be thrown out of operation so as to allow the remainder of the machine to operate, and even the inserting mechanism of one set and the series of drills of the other set may be simultaneously out of operation so that the remaining inserting and drilling mechanisms may be used for continued operation without shutting down the machine.

Thus, it will be seen that the multiple drilling and inserting mechanisms enable the machine to be maintained in operation without the disadvantageous interruptions, and high cost of maintenance, that have been prevalent in brush making machines, which have been the cause of high cost of production in the manufacture of brushes to a very large extent. Furthermore, the maintenance of the machine is greatly facilitated by the compactness of the construction involving the use of a central operating shaft for operating the drilling and inserting mechanisms by cams carried thereon.

Figs. 14 and 15 show the brush holder mechanism adapted to be used in connection with the applicants invention, which is the same as that shown in the applicants co-pending application upon Brush holders for brush making machines, Ser. No. 338,978, filed February 11, 1929, Pat. No. 1,913,863, granted June 13, 1933. In the said brush holder mechanism I have shown a main shaft IOI carried in a frame I02, which shaft has connected thereto means for driving the same at any desired speed from any suitable source of power. Surrounding the shaft IOI there is provided an annular disk-shaped brush blank holder I05 adapted to receive a succession of brush blanks I06, as, for example, tooth brush blanks, which may be continuously fed thereto by hand,

' or otherwise, at the periphery of the holder, the

arrangement being such that the completed brushes, after drilling and filling, are continually removed from the holder. As will be noted, each of the brush blanks I06 occupies a different position with regard to the center of the disk I05, each being located on its own individual radius thereon. Each of the brush blanks I06 is sup ported in the holder I 05 upon a movable carriage I09-which is provided with projections I09a, I09b to fit around the ends of and tightly hold the brush blank in place while being operated on for drilling or filling. The carriage I09 is supported by two links H and III, by means of a ball and socket joint H2 and pivot H3 allowing a certain amount of lateral play between the lever III and said pivot H3 to secure the accurate positioning of the carriage I09. The positioning of the carriage I09 is accomplished by means of a pin H4 projecting from the frame, and having a point H5 with a very acute angle at the point of the pin H4 to accurately fit within each one of a series of countersinks H6 of substantially the same shape on the face of the brush blank I06, in the rear face of the carriage I09, one of said countersinks H6 being provided for each of the holes to be drilled and filled in the brush blank I06. This pin H4 is normally held in retracted position by a spring H5a, cooperating with a shoulder I5b thereon, and the pin is moved forwardly by a plunger H50 thereon, havingan interposed spring H5d, which is moved by an adjusting pin H5e contacting with said plunger. It is by this means that the brush holder I09 is pushed forward to the drill H5 or instead the filling nozzle. A spring-pressed plunger I I! having an obtusely shaped point II 8, fits also in a similar series of countersinks H9 for roughly holding the carriage in its position between the intervals of accurate adjustment by the point H5 and while the blank on the carriage is not being operated on for drilling and filling. Said plunger H1 is' supported in a sleeve I forming a part of a sliding frame I23 to which levers H0 and H2 are secured by pivots I2I and I22, which frame is carried on a pin I24 projecting forwardly from the blank holder I 05. A spring retracted guiding rod I25, furthermore, is provided with a connecting pin I26, secured in an opening I2'I in the sliding holder I 20 for guiding and supporting the same. A spring I2'Ia. provides the plunger II! with a light forward pressure at all times. The carriage I09 is brought into its initial position for the drilling or filling of the first hole thereof by means of a cam I28 which is secured to the hub of a counter shaft I28a, said cam I28 having a cam surface I29 for cooperating with a roller I30 on an arm I 3| carried by a sleeve I 32 which has a flange I33 engaging with yokes I34 on bell crank levers I35, which are pivoted to the main frame and carry yokes I36 having releasable engagement with rollers I31 attached to the inner end of the carriage I 09. The releasable movement referred to is due to the open yokes I36 in which the rollers I31 are received. This permits the disengagement of those of the blanks not being operatedupon at any time so as to contribute to the maintenance of and the continued operation of the machine. It will be noted that a spring I38 located between the inner end of the sleeve I 32 and the frame I02 keeps the roller I30 in contact with the cam I28. This cam I28 is moved by a ratchet wheel I39 on the shaft I28a, which in turn is moved by a pawl I40 on a lever arm I4I, having a loose connection, by a link I42 to a reciprocating frame I 43 supported by a sleeve I44 on the shaft IOI inside of the sleeve I32. A cam I45 on the main shaft IOI contacts with a roller I46 on the reciprocating frame I43 so as to move the same at the proper intervals, thereby rotating the cam I28 and moving the frame I43, which carries the adjusting screws H5e so as to move the points II 4 forwardly and in turn bring the brush holders I09 up to the drills and nozzles. This reciprocating frame I 43 also has arms I41 for insuring the retraction of the guiding rods I to their initial position, thus definitely positioning the brush blank holders I09 initially.

In order to rotate the disk-shaped holder I05 from one row of holes to another, and from one blank to another, the latter carries a circular rack I48, adapted to slidably interlock with the main frame I02, having teeth I49 corresponding to the movements from one row of holes to another and from one blank to another. As shown in Fig. 15, a spring pressed plunger I50 is provided for moving the rack I48, which plunger is carried on a ball crank lever I5I supported on a pivot I 52 located on the main frame I02, the other end of which lever has a projection I53 adapted to be operated by two long projections I54 and I55 and four short projections I56, I51, I58, and I59 on the ratchet wheel I39.

While I have described my invention above in detail I wish it to be understood that many changes may be made therein without departing from the spirit of the same.

I claim:

1. A brush drilling mechanism comprising a plurality of drills each having a spindle and a driving gear thereon, means for driving the same, and a manually operated device for retracting any particular drill spindle with its gear when not in use.

2. A brush drilling mechanism comprising a plurality of drills each having a spindle and a driving gear thereon, gears for driving the same, a manually operated device for retracting any particular drill spindle with its gear when not in use, means for driving said drills from a source of power, and a detachable spider on which said multiple drills and gears are carried.

3. A brush drilling mechanism comprising a plurality of drills each having a spindle and a driving gear thereon, means for driving the same, and a device for retracting any particular drill spindle with its gear when not in use 4. A brush drilling mechanism comprising a plurality of drills each having a spindle and a driving gear thereon, gears for driving the same, a device for retracting any particular drill spindle with its gear when not in use, means for driving said drills from a source of power, and a detachable spider on which said multiple drills and gears are carried.

5. A brush drilling mechanism comprising a frame, a plurality of drills each having a spindle and a driving gear thereon located on different radii of the frame, means, including a gear on the center of said radii, for driving the same, and

5 a manually operated device for retracting any particular drill spindle with its gear when not in use.

6. A brush drilling mechanism comprising a frame, a plurality of drills each having a spindle and a driving gear thereon located on different radii of the frame, gears, including a gear on the center of said radii, for driving the same, a manually operated device for retracting any particular drill spindle with its gear when not in use, and means for driving said drills from a source of power, said frame compris'ng a detachable spider on which said multiple drills and gears are carried.

'7. A brush drilling mechanism comprising a frame, a plurality of drills each having a spindle and a driving gear thereon located on different radii of the frame, means, including a gear on the center of said radii, for driving the same, and a device for retracting any particular drill spindle with its gear when not in use.

8. A brush drilling mechanism comprising a frame, a plurality of drills each having a spindle and a driving gear thereon located on different radii of the frame, gears, including a gear on the center of said radii, for driving the same, a device for retracting any particular drill spindle with its gear when not in use, and means for driving said drills from a source of power, said frame comprising a detachable spider on which said multiple drills and gears are carried.

9. A brush drilling mechanism comprising a frame, a plurality of drills each having a spindle and a driving gear thereon located on different radii of the frame, means, including a gear on the center of said radii and smaller gears inserted between said gear and the drills, for driving the same, and a manually operated device for retracting any particular drill spindle with its gear 5 when not in use.

10. A brush drilling mechanism comprising a frame, a plurality of drills each having a spindle and a driving gear thereon located on different radii of the frame, gears, includ'ng a gear on the 10 center of said radii and smaller gears inserted between said gear and the drills, for driving the same, a manually operated device for retracting any particular drill spindle with its gear when not in use, and means for driving said drills from 15 a source of power, said frame comprising a detachable spider on which said multiple drills and gears are carried.

11. A brush drilling mechanism comprising a frame, a plurality of drills each having a spindle 20 and a driving gear thereon located on different radii of the frame, means, including a gear on the center of said radii and smaller gears inserted between said gear and the drills, for driving the same, and a device for retracting any particular 25 drill spindle with its gear when not in use.

12. A brush drilling mechanism comprising a frame, a plurality of drills each having a spindle and a driving gear thereon located on different radii of the frame, gears, including a gear on the 30 center of said radii and smaller gears inserted between said gear and the drills, for driving the same, a device for retracting any particular drill spindle with its gear when not in use, and means for driving said drills from a source of power, said 35 frame comprising a detachable spider on which said multiple drills and gears are carried.

LEONARD B. TERHUNE. 

